#include <stdio.h>
#include <string.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/stat.h>
#include "bmlib_md5.h"
#include <string.h>
#ifdef WIN32
#include <io.h>
#else
#include <unistd.h>
#endif

unsigned char PADDING[] = {
    0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
};

void MD5Init(MD5_CTX *context)
{
    context->count[0] = 0;
    context->count[1] = 0;
    context->state[0] = 0x67452301;
    context->state[1] = 0xEFCDAB89;
    context->state[2] = 0x98BADCFE;
    context->state[3] = 0x10325476;
}

void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputlen)
{
    unsigned int i = 0, index = 0, partlen = 0;
    index = (context->count[0] >> 3) & 0x3F;
    partlen = 64 - index;
    context->count[0] += inputlen << 3;
    if(context->count[0] < (inputlen << 3)) {
        context->count[1]++;
    }
    context->count[1] += inputlen >> 29;
    if(inputlen >= partlen) {
        memcpy(&context->buffer[index], input, partlen);
        MD5Transform(context->state, context->buffer);
        for(i = partlen; i + 64 <= inputlen; i += 64) {
            MD5Transform(context->state, &input[i]);
        }
        index = 0;
    }
    else {
        i = 0;
    }
    memcpy(&context->buffer[index], &input[i], inputlen - i);
}

void MD5Final(MD5_CTX *context, unsigned char digest[16])
{
    unsigned int index = 0, padlen = 0;
    unsigned char bits[8];
    index = (context->count[0] >> 3) & 0x3F;
    padlen = (index < 56) ? (56 - index) : (120 - index);
    MD5Encode(bits, context->count, 8);
    MD5Update(context, PADDING, padlen);
    MD5Update(context, bits, 8);
    MD5Encode(digest, context->state, 16);
}

void MD5Encode(unsigned char *output, unsigned int *input, unsigned int len)
{
    unsigned int i = 0, j = 0;
    while(j < len) {
        output[j] = input[i] & 0xFF;
        output[j + 1] = (input[i] >> 8) & 0xFF;
        output[j + 2] = (input[i] >> 16) & 0xFF;
        output[j + 3] = (input[i] >> 24) & 0xFF;
        i++;
        j += 4;
    }
}

void MD5Decode(unsigned int *output, unsigned char *input, unsigned int len)
{
    unsigned int i = 0, j = 0;
    while(j < len) {
        output[i] = (input[j]) |
                    (input[j + 1] << 8) |
                    (input[j + 2] << 16) |
                    (input[j + 3] << 24);
        i++;
        j += 4;
    }
}

void MD5Transform(unsigned int state[4], unsigned char block[64])
{
    unsigned int a = state[0];
    unsigned int b = state[1];
    unsigned int c = state[2];
    unsigned int d = state[3];
    unsigned int x[64];
    MD5Decode(x, block, 64);
    FF(a, b, c, d, x[0], 7, 0xd76aa478);    // 1
    FF(d, a, b, c, x[1], 12, 0xe8c7b756);   // 2
    FF(c, d, a, b, x[2], 17, 0x242070db);   // 3
    FF(b, c, d, a, x[3], 22, 0xc1bdceee);   // 4
    FF(a, b, c, d, x[4], 7, 0xf57c0faf);    // 5
    FF(d, a, b, c, x[5], 12, 0x4787c62a);   // 6
    FF(c, d, a, b, x[6], 17, 0xa8304613);   // 7
    FF(b, c, d, a, x[7], 22, 0xfd469501);   // 8
    FF(a, b, c, d, x[8], 7, 0x698098d8);    // 9
    FF(d, a, b, c, x[9], 12, 0x8b44f7af);   // 10
    FF(c, d, a, b, x[10], 17, 0xffff5bb1);  // 11
    FF(b, c, d, a, x[11], 22, 0x895cd7be);  // 12
    FF(a, b, c, d, x[12], 7, 0x6b901122);   // 13
    FF(d, a, b, c, x[13], 12, 0xfd987193);  // 14
    FF(c, d, a, b, x[14], 17, 0xa679438e);  // 15
    FF(b, c, d, a, x[15], 22, 0x49b40821);  // 16

    GG(a, b, c, d, x[1], 5, 0xf61e2562);    // 17
    GG(d, a, b, c, x[6], 9, 0xc040b340);    // 18
    GG(c, d, a, b, x[11], 14, 0x265e5a51);  // 19
    GG(b, c, d, a, x[0], 20, 0xe9b6c7aa);   // 20
    GG(a, b, c, d, x[5], 5, 0xd62f105d);    // 21
    GG(d, a, b, c, x[10], 9, 0x2441453);    // 22
    GG(c, d, a, b, x[15], 14, 0xd8a1e681);  // 23
    GG(b, c, d, a, x[4], 20, 0xe7d3fbc8);   // 24
    GG(a, b, c, d, x[9], 5, 0x21e1cde6);    // 25
    GG(d, a, b, c, x[14], 9, 0xc33707d6);   // 26
    GG(c, d, a, b, x[3], 14, 0xf4d50d87);   // 27
    GG(b, c, d, a, x[8], 20, 0x455a14ed);   // 28
    GG(a, b, c, d, x[13], 5, 0xa9e3e905);   // 29
    GG(d, a, b, c, x[2], 9, 0xfcefa3f8);    // 30
    GG(c, d, a, b, x[7], 14, 0x676f02d9);   // 31
    GG(b, c, d, a, x[12], 20, 0x8d2a4c8a);  // 32

    HH(a, b, c, d, x[5], 4, 0xfffa3942);    // 33
    HH(d, a, b, c, x[8], 11, 0x8771f681);   // 34
    HH(c, d, a, b, x[11], 16, 0x6d9d6122);  // 35
    HH(b, c, d, a, x[14], 23, 0xfde5380c);  // 36
    HH(a, b, c, d, x[1], 4, 0xa4beea44);    // 37
    HH(d, a, b, c, x[4], 11, 0x4bdecfa9);   // 38
    HH(c, d, a, b, x[7], 16, 0xf6bb4b60);   // 39
    HH(b, c, d, a, x[10], 23, 0xbebfbc70);  // 40
    HH(a, b, c, d, x[13], 4, 0x289b7ec6);   // 41
    HH(d, a, b, c, x[0], 11, 0xeaa127fa);   // 42
    HH(c, d, a, b, x[3], 16, 0xd4ef3085);   // 43
    HH(b, c, d, a, x[6], 23, 0x4881d05);    // 44
    HH(a, b, c, d, x[9], 4, 0xd9d4d039);    // 45
    HH(d, a, b, c, x[12], 11, 0xe6db99e5);  // 46
    HH(c, d, a, b, x[15], 16, 0x1fa27cf8);  // 47
    HH(b, c, d, a, x[2], 23, 0xc4ac5665);   // 48

    II(a, b, c, d, x[0], 6, 0xf4292244);    // 49
    II(d, a, b, c, x[7], 10, 0x432aff97);   // 50
    II(c, d, a, b, x[14], 15, 0xab9423a7);  // 51
    II(b, c, d, a, x[5], 21, 0xfc93a039);   // 52
    II(a, b, c, d, x[12], 6, 0x655b59c3);   // 53
    II(d, a, b, c, x[3], 10, 0x8f0ccc92);   // 54
    II(c, d, a, b, x[10], 15, 0xffeff47d);  // 55
    II(b, c, d, a, x[1], 21, 0x85845dd1);   // 56
    II(a, b, c, d, x[8], 6, 0x6fa87e4f);    // 57
    II(d, a, b, c, x[15], 10, 0xfe2ce6e0);  // 58
    II(c, d, a, b, x[6], 15, 0xa3014314);   // 59
    II(b, c, d, a, x[13], 21, 0x4e0811a1);  // 60
    II(a, b, c, d, x[4], 6, 0xf7537e82);    // 61
    II(d, a, b, c, x[11], 10, 0xbd3af235);  // 62
    II(c, d, a, b, x[2], 15, 0x2ad7d2bb);   // 63
    II(b, c, d, a, x[9], 21, 0xeb86d391);   // 64

    state[0] += a;
    state[1] += b;
    state[2] += c;
    state[3] += d;
}

void read_md5(unsigned char *file_path, unsigned char *md5sum)
{
    int fd;
    struct stat fileStat;
    unsigned int u32FileSize;
    unsigned char *file_buffer;
    ssize_t ret;

    fd = open((const char *)file_path, O_RDONLY);
    fstat(fd, &fileStat);
    u32FileSize = fileStat.st_size;
    file_buffer = (unsigned char *)malloc(u32FileSize);
    ret = read(fd, file_buffer, u32FileSize);
    if (ret == -1)
        printf("%s read %s failed\n", __func__, file_path);

    MD5_CTX md5;
    MD5Init(&md5);
    MD5Update(&md5, file_buffer, u32FileSize);
    MD5Final(&md5, md5sum);
}

void calc_md5(unsigned char *data, size_t len, unsigned char *md5sum)
{
    int fd;
    struct stat fileStat;
    unsigned int u32FileSize;
    unsigned char *file_buffer;
    int i = 0;

    MD5_CTX md5;
    MD5Init(&md5);
    MD5Update(&md5, data, len);
    MD5Final(&md5, md5sum);
}
